1. Field of the Invention
The present invention relates to an improved intra-vaginal device, and more particularly to such a device including drugs which may be controllably released in the vagina over a sustained period of time. The present invention also provides a new improved drug release method using the presently discovered intra-vaginal drug delivery system.
2. Description of the Prior Art
As an intravaginal contraceptive barrier, the diaphragm, usually prepared from a soft rubber cup with a reinforced rim that is inserted into the vagina to block access of sperm to the cervix, is an excellent alternative for women who have conditions which do not allow the use of oral contraceptives or intra-uterine-device (IUD) or who do not wish to use these methods. Although the diaphragm is usually 100% risk-free and can be a reliable contraceptive for most women, to be effective it must be used properly. Also, each individual must be specially fitted with such a contraceptive barrier thereby limiting any size standardization.
Many factors associated with the use of presently available diaphragms have prevented their widespread use. While the diaphragm acts as a barrier to most sperm, it is not normally held tightly enough in front of the cervix to prevent entirely the passage of all sperm around the rim. Therefore, the device is used in most instances with a spermicidal cream or jelly. The vaginal spermicides are often messy and tend to flow out of the vagina. Replenishing the spermicide can be expensive if the diaphragm is used frequently.
The use of conventional diaphragms not only interrupts normal sexual intercourse, but also it presents problems with maintenance associated with diaphragm washing, sterilization, drying, powdering, and inspection prior to insertion on reuse.
Numerous contraceptive devices have been developed to eliminate the disadvantages of current reusable diaphragms. Prior art annular devices provide controlled release of surfactant-type spermicides in the vagina, but that do not act as a barrier to sperm deposition on or in the area of the cervix. Devices with compartments that substantially cap or block the cervix and provide controlled release of spermicidial surfactants have been disclosed; however, these devices are not disposable, and they are designed to remain in the vagina and release spermicide during the time between menstrual periods. Because of this length of use, they may develop problems with infection, odor, or discomfort, and they are less suited for women who engage in sexual intercourse infrequently.
These and other defects in prior art devices are now overcome by practice of the present invention.